I believe you are referring to Mirena. Well some of the side effects are mentioned below:

1. BREST pain

2. Spinal pain and Headaches.

3. Acne is another main side-effect of Mirena after insertion. 4. Women using Mirena often discharges a milky white colored fluid after regular intervals. 5. Common cold and infections are also seen in case of using Mirena. 6. Women generally feel elongated menstrual periods with pain. Also researches confirmed that women who have taken Mirena generally have heavier menstrual periods than in the normal case. This is something very disturbing. It is also the fact that about 18 to 25 % of women feels that they are experiencing no more periods. 7. Other side effects include ovarian cysts, Sinus infections and weight gain which are dangerous symptoms for using Mirena. The researched percentage that is calculated for the women using Mirena and developing ovarian cysts at the same time is about 10 to 13 %. Along with Sinus there is another type of infection called the Yeast infection. Yeast infection also affects the women experiencing Mirena.